Comparison website Creditworld director Roland B. Bleyer says under recent law changes, credit providers must include a comparison rate when advertising fixed-term credit, but consumers should check they are not paying inflated prices when taking up low-interest finance deals.

"With these offers coming out, what they are generally after is for you to pay full recommended retail price to get that rate," he says.

"So, for example, you might be able to get a $5000 discount on a car if you haggled with a broker, but you wouldn't get that if you took up the comparison rate.

"They may want the full recommended retail price to give the zero comparison rate."

A comparison rate is based on the average annual percentage rate that includes interest payments and fees within one rate, and reveals the total annual cost to the borrower.

Bleyer warns consumers to be wary before signing on the dotted line of finance deals and to check the fine print.

"There is often a balloon payment of up to 50 per cent at the end," he says. "In these cases the comparison rate doesn't actually help them out because the balloon payment is not included in the rate."

A balloon payment is a large payment due at the end of a mortgage or a loan.

MoneySmart senior executive Robert Drake says consumers should be mindful of traps with comparison rates.

"The comparison rate does not include all fees and charges," he says.

"It only includes fees that will definitely be charged to a consumer, for example an establishment fee, but the comparison rate won't include contingent fees dependent on consumer behaviour, such as the cost of early termination."

"The trap for consumers to consider is the interest that accrues after an interest-free period if you haven't paid off the cost of your purchase."

A spokesman from consumer group Choice says customers should ensure that "they are comparing apples with apples."